This invention relates generally to apparatus for raking up rocks from the ground and, more particularly, to apparatus adapted to be attached to a self-propelled vehicle and adapted to rake up the rocks as the vehicle travels over the ground.
In our prior application, Ser. No. 08/387,305 (hereafter our prior application) we disclosed and claimed apparatus for raking rocks which proved to be a highly effective advance in the art. This application is intended to describe and claim certain improvements therein. In one aspect, the rotor construction which was subsequently incorporated into the rock raking apparatus, has a new and improved structure. This application is also intended to describe at greater length certain important functional relationships between elements of the structure described in detail in our prior application. In other words, our prior application adequately described the structure, and how to make an apparatus capable of meeting the benefits of the invention. The present application better describes functional relationships between those disclosed structural elements.
In our prior application, the rotating brush was disclosed as being adapted to clean the surface of the rotor. That is an important function, but it will be found that the brush when positioned and operated as described in our prior application, performed several additional functions. One of those is the deflection of rocks propelled by the rotor, from the brush into the rear of the bucket. The second is the prevention of formation of a rock barricade at the entrance of the bucket, with the result being the ability of the apparatus to reliably fill the bucket. These functions, it will be found, are accomplished when one follows the structural disclosure of our prior application.
Rock raking apparatus is disclosed in Baskett U.S. Pat. No. 5,060,732. In general, the apparatus comprises a raking unit having a toothed rotor supported to rotate about a laterally extending axis by two laterally spaced side walls. A bucket is pivotally connected to one end of the raking unit and collects the rocks raked up by the unit. The bucket also is pivotally connected to lift arms of the vehicle and, by actuating such arms, the raking unit and the bucket may be lifted from the ground to a transport position. After the raking unit has been moved to a dumping location, an actuator between the vehicle and the bucket is operated to cause the bucket to pivot to an open position relative to the raking unit and enable dumping of the rocks. In order to enable lifting of the raking unit and opening of the bucket, additional actuators are required between the raking unit and the bucket.
The rotor of the raking unit of the Baskett patent is in the form of a hollow drum. Laterally extending and angularly spaced channels are welded to the periphery of the drum and each carries a plurality of laterally spaced specially shaped teeth. The teeth/channel assemblies are relatively complex and non-symmetrical, and can create problems in that small rocks and dirt tend to become trapped between the teeth and against the drum and are carried over the drum rather than being raked up.
Additional rock raking apparatus is disclosed in Baskett U.S. Pat. No. 4,113,023 and Erholm U.S. Pat. No. 4,364,434. Those devices, however, require extremely complex raking units in that the apparatus of the Baskett '023 patent utilizes multiple rotors while the apparatus of the Erholm patent utilizes endless chains to carry the raking teeth.